Technical Field
The present disclosure relates to a wiring substrate, a manufacturing method of the wiring substrate and an electronic component device.
Related Art
In the related art, a wiring substrate for mounting thereon electronic components such as a semiconductor chip has been known. In the wiring substrate, a bump of the semiconductor chip is flip chip-connected to a connection pad of the wiring substrate through a soldering.
[Patent Document 1] Japanese Patent Application Publication No. Hei. 7-202419A
[Patent Document 2] Japanese Patent Application Publication No. 2002-374066A
[Patent Document 3] Japanese Patent Application Publication No. 2010-67887A
As described later in paragraphs of preliminary matters, in the wiring substrate, an upper surface and side surfaces of a wiring layer are formed with unevenness having the same surface roughness by roughening processing so as to secure adhesiveness between the wiring layer and an insulation layer.
For this reason, in the wiring substrate that is to be used in a high-frequency band, propagation loss of a high-frequency signal increases due to an influence of the unevenness of the wiring layer.